Reply in line [anand] Regards, Anand
On Sat, Sep 18, 2010 at 5:30 AM, anand <anandmad...@gmail.com> wrote: > > > Sent from my Nokia phone > -----Original Message----- > From: Paul Kyzivat > Sent: 18/09/2010 2:25:34 am > Subject: Re: [Sip-implementors] sdp missing m line > > > > On 9/17/2010 7:45 AM, anand madhab wrote: > > Hi, If m line is missing in invite request and 180, 200 response then > what > > will be senario ? > > I dont understand the case, I mean i want to make a call with initially > > putting a person in hold ? please explain > > does caller need to reject the call > > Your question isn't entirely clear. Can you show call flow? > > I am guessing that the INVITE has SDP with one m-line, and the response > has SDP with no m-line ??? > > > [anand] As per rfc 3264 says answer should contain adjectly same number of line as many present in offer, so is it possible for callee to respond without m line ? > If so, I would expect the caller to send BYE and drop the call. The > answer SDP must have the same number of m-lines as the offer. > > We don't usually specify behavior for non-conforming cases (which this > is), so the caller isn't *required* to send a BYE. But behavior after > that is undefined. > > Are you implementing the UAS, and wanting to prevent media from flowing > immediately as the call is established? > > You can do a number of things, depending on exactly what you want to > happen: > > - you can respond with an answer with matching m-line, with real address > and port, and include an a=sendonly or a=inactive to prevent media from > flowing to you. You have indicated that you are willing to use this > media, but not yet. In case of RTP-based media, *RTCP* will still flow. > > - you can respond with an answer with matching m-line, and a non-zero > port, but with an address (c=) of 0.0.0.0. This is similar to prior, > except nothing will flow to you. > > - you can respond with an answer with matching m-line, with a zero port. > This says you are rejecting the use of this media, but haven't rejected > the call. This is valid in principle, but its likely to upset some UAs, > because they don't know what they are supposed to do. > > Paul > > -- Thanks & Regards Anand Madhab _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
